Pump and motor assembly



March 24, 1942. H. LEOPOLD PUMP AND MOTOR ASSEMBLY Filed Jan. 20, 1940 nx Q w m A- l mu I Q I I V %M mm M I l w H H l NI on mw mm. 1.. W M 1 r%N. a I m ow mN x mm Q .w. m \M mq l K I. m I 1 I l mm 19/3 3 w zINVENTOR HUGO LEOPOLD ATTORN Patented Mar. 24, 1942 2,277,333 PUMP ANDMOTOR ASSEMBLY Hugo Leopold, Davenport, Iowa, assignor to Micro-Westco,Inc., Bcttendorf, Iowa, at corporation of Delaware Application January20, 1940, Serial No. 314,871

1 Claim.

This invention relates to pump and motor assemblies, andmoreparticularly to an improved connection for pumps having a rotor mountedon a shaft and actuated by an electric motor, such, for example, asturbine and centrifugal pumps.

There are numerous applications for pump units which include asupporting structure carrying a pump and a drive motor therefor.Depending upon the amount of water or other fluid to be handled by thepump, and the head against which the pump must operate, the power of themotor is subject to considerable variation. For example, a pump todeliver a given quantity of liquid against a certain head, will requirea motor of specified power, but the same pump to deliver l5v the samequantity of liquid against a higher head will require a drive motor ofincreased pow- Similarly, if the same quantity of liquid is to bedelivered by the pump against a lower head, a less Dowerfulmotor may beemployed.

In previous'practice, pump manufacturers customarily mounted the pumprotors directly on the motor shafts. Accordingly, where a pump of onesize or model was designed for use under different operating conditions,it was necessary for the manufacturer'to maintain a plurality of motorsizes in stock, with their shafts machined and finished for the rotor ofthat particular pump.. Hence, for each pump produced, the manufacturerhad a separate line of motors in stock. Even though some motors were ofsufficient power to drive different pumps, they could not beinterchangeably used becausejthe pump rotors would not fit thediiferent'motor shafts;

Some pump and motor assemblies have the pump shafts'journaled in thepump housing and connected to the motor shaft by'means of aflexible-coupllng. This'type of construction, however, is expensivebecause of the. necessity for having additional journals to carry thepump r shaf-t and bec'ausof; the coupling cost. Furthermore, a morecompact and a neater unit hav ing improvedoperating characteristics may'be provided when the rotor is "rigid with the motor-j It is, therefore,aprincipal; object-of the pres?- ent invention tcl rovidea' pump andmotor as sembly in which the rotor of the pump is secured on a shaftwhich is rigidly connected to the motor. shaft, and in whichthe shaft onwhich the rotor is mounted may be quickly and easily disconnected fromthe shaft'ofthemotor,

Another object is to provide a connection for a pump and motor unitwhich, facilitates the interchangeof anumber of pumps with a singlemotor without disassembling the .parts of the pump or the motor.

.Another object is to provide a pump and motor assembly in which thepump rotor is secured on a shaft which is rigidly secured to the motorshaft pump and drive motor assembly utilizing my improved connection;

The unit comprises a base or supporting structure l, which may pe a partof or integral with the housing for drivemotor 2. Annular casing 3 ofthe pump ismounted between inner and outer cover plates 4 and 5,respectively, and is provided with a pressure developing 'channel 6,which may be of conventional form.

A supporting bracket. 1 of "annular or somewhat cylindrical shell-likeform is secured to one end of the supporting structure I, or motor cas-'ing, by meansof bolts 8. The end of the supporting bracket o'ppositethe,motor isprovided with a circular, recess which telescopically receivesanaxially extending .collar 9, formed on the inner pump cover, plate 4.

Bolts Ill, having their heads on tileihside or I the cylindricalbracket1; extend through drill holes in the end of the bracket, and. in radialflange ll of the cover plate}, and are threaded into the pump casing'3,thus securing the latter and the cover plate 4 to the. outer end of thesupporting bracket. The, outer cover plate 5, in which is formedcentralpumpinlet passage [4, is secured tothe pumpcasing 3 bybolts 15.

The motor 2 rnay, beof conventionalconstruc tion, and has a'sha'ft, l6journaledin bearings ll, mounted in theend'of the: motor housing. In thedrawing, only the bearing, ll for the right} handaendbf tliemotor'shaftis illustrated, it be ing understood that the left-hand bearing is V of5 similar construction. Preferably, roller or ball bearings are used, asillustrated, and alubricant chamber l8. may be provided aroundthe'recess for the bearing, the inner end'of the chamber being sealed bya packing ring l9 that embraces the motor shaft. w l

On the outside of the bearing illustratedthe motor shaft. I 5 is formedwith a spigot or inter ,nal connecting "end which includes an externallythreaded portion 20, and a frusto conicalftaper portion 2] which extendsas a continuation of the threaded portion to the tip of the shaft.

A supplementary or extension shaft 23 for pump rotor 24 (to be laterdescribed) is provided with a bell-shaped or external connecting end 25,telescopically received on the spigot end of the motor shaft [6. Thebell end of the rotor shaft has an internally threaded portion 26 and'aninternal frusto-conical socket 21 which receive, respectively, thethreaded portion and frusto-conical portion 2| of the motor shaft, and aclearance chamber 28 is formed at the inner end of the frusto-conicalsocket 21.

The threads in the bell and spigot connection of the shafts l6 and 23are arranged so that the motor shaft is screwed or turned into the pumpshaft by rotation of the motor in its normal driving direction. In thismanner, the threads press the taper portion 2| of the motor shaft intothe frusto-conical socket 21 provided therefor in the bell end 25 of therotor shaft to assure accurate axial alignment of the rotor shaft 23with respect to the motor shaft l6.

While the specific dimensions of the frustoconical portion 21 of theshaft l6 are not critical, it is preferable that this taper portion beof greater length than its widest diameter so as to effect accuratealignment of the shaft, and to prevent wobbling of the rotor shaftduring operation.

end portion 29 of the shaft 23, and is secured in place by a bolt 30screwed into the end of the shaft. Any type of rotor may be employed,the

- specific construction not being a part of the character. A gland orfollower 38 is received on the shaft 22- and is threaded into the hub toclose the packing chamber 36 and compress the packing'material 31 sothat the latter tightly em-' braces the shaft 23 and prevents the flowof liquid along the shaft througlr the cover plate 4.

The rotor 24 is received on a reduced diameter described above, it ispossible for a pump manufacturer to make or have made by a motormanufacturer, motors of different size or power, all equipped with astandard shaft having thespecific type of spigot end formation set forthabove. All of the pumps to be assembled with different size motors,regardless of their size or capacity, have rotor shafts formed with bellends which will make connection with the standard motor shaft.Accordingly, the pump manufacturer need only keep in stock a single lineof motors of each size, all of which will fit and are interchangeablewith, all of the pumps with which they may be used.

In the event that after installation of a certain pump it is found thatchanged conditions require a slightly different capacity, it is possibleby use of the present invention to substitute a different motor with aminimum of trouble, and without removing the pump from the liquidcircuit in which it is connected. There is thus obtained a materialeconomy which is desirable from the point of view of the public. By thepresent invention, the unique connection providedfor a pump and motorassembly assures a rigid and accurate connection between the pump and,motor shafts while permitting facile disassembly of the unit if desired.

It is an important feature of the present invention that the rotor shaft23 is wholly supported by the motor shaft II, the latter being rotatablymounted in the journals l1 carried by the supporting structure or motorhousing. The stufling box I! is not relied upon to support the shaft 23,but only to effect a fluid tight seal with the shaft so as to preventleakage into or out of the chamber in the pump casing 8. If

,the stufling box 35 were employed as a bearing for the shaft 23,excessive wear of either the packing material or the shaft would be.likely to occur, resulting in leakage and requiring early replacement ofthe pump shaft.

It is to be noted that the bell end 25 of the rotor shaft 22 extendsinto the lubricant chamber ll of the motor journal. Desirably a sealingring 39 is carried by the motor journal structure and arranged toembrace the bell end 25 to prevent loss of lubricant from the chamber, II.

One or more side openings 40 maybe provided in the supporting bracket 1to allow access to the packing gland or follower II, and for use inservicing the pump and rotor assembly.

By the arrangement shown'in the drawing and The principles of thepresent invention may be utilized in various ways, numerousmodifications and alterations being. contemplated, substitution of partsand changes in construction being resorted to as desired, it beingunderstood that the embodiment shown in the drawing and described aboveis given for purposes'of explanaof the pump assembly, said free endbeing formed with an external conical' taper, a rotor in the pumpcasing, an unjoumaled stub shaft having one end thereof formed with anlntemal conical taper to -mate with the taper of the main shaft and theother end thereof extending into the casing and rotatably mounting therotor therewithin, said housing structure including means forming alubricant chamber surrounding the free end of the main shaft and'ificliiding sealing means defining a circular opening concentric withthe rotational axisof the main shaft, said one end of the stub shaftextending through said openiIl-\g1t0 the lubricant chamber and having arunning fit withthe sealing means whereby the circular line ofconnection between the mating parts of the shafts and-at said one end'of the stub shaft is disposed within the lubricant chamher to protectthe connection against rusting and

